[unreadable] [unreadable] This R03 application to NIDA is in response to RFA-DA-05-005, Secondary Analysis of the NESARC and NSPY Datasets; we propose a secondary analysis of two national datasets to examine the trends in (1) the prevalence and correlates of nonmedical use of prescription drugs (NMPD) and prescription drug use disorders (PDUD), (2) the prevalence and correlates of concomitant NMPD and alcohol use, including alcohol use disorders (AUD), and (3) age of initiation of NMPD and other drug use in the U.S. between 1991- 1992 and 2001-2002. The nonmedical use of several classes of controlled substances (e.g., anxiolytics, opioid analgesics, sedative/hypnotics, and stimulants) has increased in the past decade in the U.S. While there are many potential consequences associated with concomitant NMPD and alcohol use, the association between these two substance use behaviors has received very little attention in national population-based research. In order to address these gaps, we propose to conduct a secondary analysis of the 1991-1992 National Longitudinal Alcohol Epidemiogical Survey (NLAES) and the 2001-2002 National Epidemiology Survey on Alcohol and Related Conditions (NESARC); each feature large nationally representative samples of approximately 43,000 adults 18 years of age and older in the U.S. The NLAES and NESARC datasets will be analyzed using a statistical software package capable of taking a complex sample design into account while performing multivariate analyses. The specific aims of the proposed project are to assess: (1) trends in the prevalence and correlates of NMPD and PDUD between 1991-1992 and 2001-2002; (2) trends in prevalence and correlates of (a) concomitant NMPD and alcohol use and (b) concomitant PDUD and AUD between 1991-1992 and 2001-2002; and (3) trends in age of initiation of NMPD and other drug use between 1991-1992 and 2001-2002. The findings of this study will enhance our understanding of nonmedical use of prescription drugs, prescription drug use disorders and emerging forms of substance use. It will help identify risk factors for substance abuse. Most importantly, the findings will provide guidance for the prevention, assessment, and treatment of prescription drug abuse. [unreadable] [unreadable]